In transmission devices known from the prior art, such as automatic torque converters, a shifting element such as a clutch or brake is actuated by means of a pilot-controllable control valve device and, in functional connection with it, a shifting valve device which is also pilot-controllable. By means of a pressure regulation device, the pilot pressure for the control valve device and the shifting valve device is set as a function of an electric control signal, the pressure regulation device having a defined working pressure range which is usually substantially lower than the actuation pressure of the shifting element. In order to be able to actuate the shifting element with pressure values higher by comparison with the pilot pressure of the control valve device and the shifting valve device, the control valve device is connected downstream from the pressure regulation device, in the area of which the pilot pressure of the pressure regulation device is changed to a higher level.
During driving operation of a vehicle constructed with the transmission device it must be ensured that in the fully engaged operating condition of the shifting element, the shifting element has its maximum transmission capability and operates without slip. For this the actuation pressure at the end of the control pressure range of the actuation pressure is increased abruptly to a higher pressure value that usually corresponds to a so-termed system pressure. The switch-over or at least almost abrupt increase of the actuation pressure is brought about by the shifting valve device controlled in parallel by the pressure regulation device, which however is only actuated, or brought from a first to a second switch condition, at high pilot pressures.
By means of the shifting valve device, the feedback of the actuation pressure to the control valve device is deactivated when the shifting valve device is in a second switch condition, so that the control valve device is changed from a so-termed modulation position to an operating condition in which the system pressure applied at the control valve device is passed through completely in the direction toward the shifting element.
However, the disadvantage of this is that the control valve devices known from the prior art occupy an undesirably large amount of installation space in the axial direction, and the control characteristics of the control valve device are impaired to an undesired extent due to the axial length of a valve slide of the control valve device.